i have an iphone 3g 8gb.
It only turns on when plugged in usb.
i tried to put into DFU it works.
i Restore to any firmware
3.1.3
cUSTOM FIRMWARE...
it still turns off during restore.( about 40 seconds after restoring)
Pls help me

I'd say a dead battery, relatively cheap nowadays and a straight forward swap so try a new battery and see how you get on. (At the start of any restore for some reason the iphone is told to stop using USB power and only run off battery - if your battery is not holding a charge it obviously will not run the phone hence the restore fails)

Also, is it charged when your restoring it? You should let it charge for like 30 mins from dead before attempting to restore.

thanks for your reply...
i let it charge whole day but there is no battery charging display at all.... it is not charging at all....
the phone cannot reboot when the phone was disconnected when in the process of restore...
so base on advice there is a need to replace the battery???
Please do advice...........

Once you have replaced the battery you will need to charge it from a mains charger, when you plug it in you should get the red battery and lightening bolt symbol - then after a while the phone should try to boot once sufficient charge is in the battery. USB ports most likely won't give enough power for a first time charge of a new battery.

Once you have replaced the battery you will need to charge it from a mains charger, when you plug it in you should get the red battery and lightening bolt symbol - then after a while the phone should try to boot once sufficient charge is in the battery. USB ports most likely won't give enough power for a first time charge of a new battery.

Thanks for your kindness reply...
I charge and nothing is on display.
No red battery logo.
Apple logo up for around 40 seconds.
SHUTS DOWN again.
Please ADVICE....

I was backing up my iphone files in my computer but my computer suddenly turns off and I open my computer and trying to restore backup files but it says it has some error and backing up files automatically cancelled I could open my Iphone just help me how to handle this problem?